Purpletop Vervain
Verbena bonariensis
A tall, slender perennial with square, open stems and dark green, lance-shaped leaves with serrated margins, topped by tight clusters of vibrant purple-violet flowers.
- Light
- Full sun, requiring at least 6 hours of direct sunlight daily for optimal blooming and sturdy stem growth.
- Water
- Moderate watering needs; drought-tolerant once established. Water deeply when the top inch of soil dries out, taking care not to waterlog.
- Growth
- Upright, airy perennial herb growing 3 to 6 feet tall and 1 to 3 feet wide, featuring a fast growth rate.
Care instructions
Plant in a location with abundant direct sunlight and fertile, well-draining soil. Water regularly to establish, then keep slightly moist or allow to dry between waterings. Apply a balanced slow-release fertilizer in early spring.
Growing details
Sunlight
Full sun, requiring at least 6 hours of direct sunlight daily for optimal blooming and sturdy stem growth.
Watering
Moderate watering needs; drought-tolerant once established. Water deeply when the top inch of soil dries out, taking care not to waterlog.
Soil
Prefers moist, well-drained loamy or sandy soils with a neutral to slightly acidic pH (6.0 to 7.5).
Hardiness zone
USDA Hardiness Zones 7 to 11 (often grown as an annual in cooler regions).
Growth habit
Upright, airy perennial herb growing 3 to 6 feet tall and 1 to 3 feet wide, featuring a fast growth rate.
Bloom season
Blooms continuously from early summer through late autumn, producing dense terminal clusters of small, vivid purple flowers.
Propagation
Propagated easily by seed sown indoors in early spring, softwood cuttings in summer, or self-seeding in mild climates.
Common pests & issues
Susceptible to powdery mildew in poor air circulation or high humidity; can occasionally attract aphids, spider mites, or whiteflies.
Similar species
Verbena rigida (Slender Vervain) grows much shorter and denser; Verbena hastata (Blue Vervain) features longer, erect, candle-like flower spikes.